If you have such a photo in your MY PHOTOS queue, all you need do is set the Language as close as you can to what you think it is, or leave it and skip that photo while transcribing. If it looks like Chinese, put that, although it might actually be Japanese. A native reader can quickly tell the difference.
Please do not do a partial transcription; sometimes the dates are readable, but the names are not. Such transcriptions are essentially useless as they will not show up in any searches.
Best ot SKIP any photos in any language that you cannot at least read the family name.
Also do not try to transcribe stones where the language seems to be our alphabet with some characters looking strange. The Cyrillic alphabet is used for Russian, Ukrainian, and other Slavic languages. They are very different alphabets compared to English, French, Spanish, etc.
Glad you asked this question. The SKIP button is powerful. When in doubt, SKIP is the best option.